1. Field of the Invention
The present invention relates to an acidic gas separation module which selectively separates acidic gas from raw material gas. Specifically, the present invention relates to a spiral-type acidic gas separation module obtained by winding a laminate having an acidic gas separation film.
2. Description of the Related Art
In recent years, a technique of selectively separating acidic gas such as carbon dioxide from raw material gas (gas to be treated) has been promoted for the purpose of production of hydrogen gas or purification of natural gas. For example, an acidic gas separation module that separates acidic gas from raw material gas using an acidic gas separation film through which acidic gas selectively permeates has been developed.
Specifically, JP1992-215824A (JP-H04-215824A) discloses an acidic gas separation module obtained by winding a laminate containing an acidic gas separation film around a central tube (central permeable material collection tube), in a tube wall of which through-holes are formed and which is used for collecting separated acidic gas, multiple times.
The acidic gas separation module disclosed in JP1992-215824A (JP-H04-215824A) is a dissolution-diffusion type acidic gas separation module using a so-called dissolution diffusion film as an acidic gas separation film. The dissolution diffusion film separates acidic gas from raw material gas using differences in solubilities of acidic gas and materials to be separated therefrom in a film and differences in diffusibility in a film.
Further, JP4621295B discloses an acidic gas separation module (experimental device) that divides a space into a raw material chamber and a permeation chamber using an acidic gas separation film, supplies raw material gas (mixed gas formed of CO2, H2, and H2O) to the raw material chamber, and removes the acidic gas selectively separated (through permeation) by the acidic gas separation film from the permeation chamber.
The acidic gas separation module disclosed in JP4621295B is a facilitated transport type acidic gas separation module using a so-called facilitated transport film as an acidic gas separation film. The facilitated transport film includes a carrier reacting with acidic gas in the film and separates acidic gas from raw material gas by the acidic gas being transported to the side opposite to the film using the carrier.
In such an acidic gas separation module, with a so-called spiral-type acidic gas separation module obtained by winding a laminate that has an acidic gas separation film around a central tube having through-holes on the wall surface (laminate is wrapped around the central tube), as described in JP1992-215824A (JP-H04-215824A), the area of the acidic gas separation film is able to be very greatly increased. Accordingly, the spiral-type acidic gas separation module is capable of performing a treatment with high efficiency and is markedly effective.